Synthesis and Biological Evaluation of 3-Alkyl-1,5-Diaryl-1H-Pyrazoles as Rigid Analogues of Combretastatin A-4 with Potent Antiproliferative Activity.

• Main Authors: Qile Xu, Huan Qi, Maolin Sun, Daiying Zuo, Xuewei Jiang, Zhiyong Wen, Zhiwei Wang, Yingliang Wu, Weige Zhang
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2015-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC4462585?pdf=render

A series of novel 3-alkyl-1,5-diaryl-1H-pyrazoles were synthesized as combretastatin A-4 (CA-4) analogues and evaluated for antiproliferative activity against three human cancer cell lines (SGC-7901, A549 and HT-1080). Most of the target compounds displayed moderate to potent antiproliferative activity, and 7k was found to be the most potent compound. Structure-activity relationships indicated that compounds with a trimethoxyphenyl A-ring at the N-1 position of the pyrazole skeleton were more potent than those with the A-ring at the C-5 position. Tubulin polymerization and immunostaining experiments revealed that 7k potently inhibited tubulin polymerization and disrupted tubulin microtubule dynamics in a manner similar to CA-4. Computational modelling demonstrated that the binding of 7k to the colchicine binding site on microtubules may involve a similar mode as CA-4.